Field of the Invention
The present invention relates to a gelling agent containing N-acyl acidic amino acid dialkylamide having a particular DL form ratio (component A). In addition, the present invention relates to a gel composition, particularly a rod-like gel composition, containing the N-acyl acidic amino acid dialkylamide (component A), an oily base (component B), and an ester of acylamino acid and dimer diol and/or an ester of acylamino acid and fatty acid and dimer diol (component C).
Discussion of the Background
Heretofore, N-acyl-L-amino acid dialkylamides such as N-lauroyl-L-glutamic acid dibutylamide, N-2-ethylhexanoyl-L-glutamic acid dibutylamide and the like have been used as gelling agents for oily bases. While they are known to gel various oily bases, since they have high melting points and show low solubility in oily bases, dissolution thereof requires a high temperature of, for example, 150° C. or above, which is not entirely preferable when substances having poor thermal stability and volatile components are blended.
To solve this problem, a method of combining N-acyl-L-amino acid dialkylamide and sugar fatty acid ester and/or polyol fatty acid ester (patent document 1: JP-A-2009-114161), and a method of using in combination with a particular organic solvent such as behenyl alcohol, octyldodecanol and the like (patent document 2: JP-A-2005-298635) have been proposed. However, they impose a limitation on the formulation design in that a particular component in a particular amount needs to be blended, and further, a gel composition superior in transparency and strength may not be obtained in some cases. As such, they are not necessarily useful solving measures.
On the other hand, gel compositions prepared using N-acyl-L-amino acid dialkylamide sometimes lack texture (e.g., spreadability, compatibility etc.) when applied to the skin or hair. Rod-like cosmetic agents such as rouge and the like are mainly composed of a gelling agent, and an oily base such as wax, waxes, paste oil, liquid oil and the like, and various sensory qualities have been realized by changing the amounts of these. However, use of a large amount of wax and paste oil tends to cause bad sense of use, for example, stickiness, moisture, close adhesiveness and the like. In recent years, therefore, attempts have been made to prepare cosmetic agents with reduced amounts of wax and paste oil.
For example, patent document 3: JP-A-2010-260824 and patent document 4: JP-A-2010-260825 disclose a combined use of N-acyl-L-amino acid dialkylamide and dimer acid ester to afford a superior texture. However, even such use sometimes fails to achieve a sufficient texture.